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<h2><a name="SECTION0017370000000000000000"></a><a name="timer-objects"></a>
<br>
15.3.7 Timer Objects 
</h2>

<p>
This class represents an action that should be run only after a
certain amount of time has passed -- a timer.  <tt class="class">Timer</tt> is a
subclass of <tt class="class">Thread</tt> and as such also functions as an example of
creating custom threads.

<p>
Timers are started, as with threads, by calling their <tt class="method">start()</tt>
method.  The timer can be stopped (before its action has begun) by
calling the <tt class="method">cancel()</tt> method.  The interval the timer will
wait before executing its action may not be exactly the same as the
interval specified by the user.

<p>
For example:
<div class="verbatim"><pre>
def hello():
    print "hello, world"

t = Timer(30.0, hello)
t.start() # after 30 seconds, "hello, world" will be printed
</pre></div>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><span class="typelabel">class</span>&nbsp;<tt id='l2h-3465' xml:id='l2h-3465' class="class">Timer</tt></b>(</nobr></td>
  <td><var>interval, function, args=[], kwargs={}</var>)</td></tr></table></dt>
<dd>
Create a timer that will run <var>function</var> with arguments <var>args</var> and 
keyword arguments <var>kwargs</var>, after <var>interval</var> seconds have passed.
</dl>

<p>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-3466' xml:id='l2h-3466' class="method">cancel</tt></b>(</nobr></td>
  <td><var></var>)</td></tr></table></dt>
<dd>
Stop the timer, and cancel the execution of the timer's action.  This
will only work if the timer is still in its waiting stage.
</dl>

<p>

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<span class="release-info">Release 2.5.1, documentation updated on 18th April, 2007.</span>
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